Floating locking device for chairs



April 23, 1963 R. A. CRAMER, JR 3,086,744

' FLOATING LOCKING DEVICE FOR CHAIRS Filed May 1, 1961 2 Sheets-Sheet 1 ENTOR. lacy A. CQAMHZ J11.

aw ATTO EYS VIII/IIIII/liii April 23, 1963 R. A. CRAMER, JR 3,085,744

FLOATING LOCKING DEVICE FOR CHAIRS Filed May 1, 1961 2 Sheets-Sheet 2 ATTORNEYS ilnited rates $386,744 FLOATING LOiZKlNG DEVICE FOR CHAR; Roy A. Cramer, J12, Kansas Qity, Mm, assignor to Cramer Posture Chair Company, Inc, Kansas City, Kane, a corporation of Missouri Filed May 1, 1961, Ser. No. 186,836 1 Claim. (Cl. 248406) This invention relates to an adjusting locking device for chair bases and more particularly to a locking nut used in connection with means for raising and lowering the seat of the chair relative to the base portion and locking the same in place for easy adjustment of the height of the chair and holding it in adjusted position.

This application is a continuation in part of my application Serial No. 7,323 filed February 8, 1960, now Patent No. 2,987,110.

With locking devices heretofore devised, the pedestal of the chair would sometimes bind in the hub of the base of the chair and thus prevent easy adjustment of the pedestal with respect to the base through turning of the pedestal therein.

It is therefore the principal object of the present invention to provide a threaded pedestal for a chair cooperating with the floating locking nut carried by the base of the chair wherein a tolerance will be provided between the locking nut and the sleeved hub member of the base to prevent binding of the pedestal therein.

Other objects of the present invention are to provide a base having a sleeved hub member with a socket portion therein larger than the diameter of the pedestal of the chair; to provide a sleeved locking nut in said socket internally threaded to engage the threaded pedestal of the chair; to provide means for holding the locking nut aligned with the sleeved hub member; to provide a collar for free slidable movement vertically of the pedestal, the collar having an inside circumference slightly larger than the outside diameter of the threaded pedestal and having means to engage the pedestal to rotate therewith; to provide means carried by the collar for engaging the depending hub of the chair seat, and to provide means for holding the collar in adjusted position.

Other objects of the present invention are to provide means on the collar cooperating with notches in the floating locking nut to hold the pedestal and lock nut stationary during use of the chair after it has been adjusted.

Still further objects of the present invention are to provide a hub member extending above the base of the chair having a socket for receiving the floating locking nut and means for retaining the locking nut in place.

Still further objects of the present invention are to provide a base having a cylindrical hub member substantially flush with the top of the base for receiving the threaded pedestal; to provide a washer member having an upstanding collar portion surrounding the threaded pedestal and having a bracket member extending from one side upwardly substantially in vertical position spaced from the pedestal; to provide a locking nut threaded on the pedestal and having its lower side provided with a socket to engage over the upstanding collar portion of the washer, to provide a locking nut with an opening in the side thereof; to provide a pin or threaded screw carried by the bracket for engaging in said opening in the nut to prevent rotation thereof; and to provide a ring member for the pedestal having a dish-shape and depending downwardly partially surrounding the locking nut when in locking position; and to provide a device of this character, simple and economical to manufacture.

FIG. 1 is a fragmentary side view showing the collar on the pedestal disengaged from the hub and the floating locking nut in place.

3,686,744 Patented Apr. 23, 1963 "ice FIG. 2 is a cross-sectional fragmentary view showing the collar in elevated position and locked in place with the hub of the chair seat.

FIG. 3 is a fragmentary view showing the locking nut in lowered position when the chair is in adjusted position.

FIG. 4 is a cross-sectional fragmentary view particularly illustrating the fastening of the floating locking nut in place.

FIG. 5 is a cross-sectional fragmentary view showing a modified form of hub member in the base of the chair and the floating locking nut therein.

FIG. 6 is a cross-sectional view taken on a line 6-6, FIG. 5.

FIG. 7 is a cross-sectional fragmentary view of a still further modified form of the invention with the floating locking nut above the base of the chair and the washer locking member therefor.

Referring more in detail to the drawings:

1 designates a chair base having a sleeved hub 2 depending downwardly from the top 3 of the base having a cylindrical opening 4 for receiving a threaded pedestal 5. The base has the usual legs (not shown) secured to the hub and a seat frame 6 has 2. depending hub or boss member 7 extending downwardly from the seat frame which provides a socket 8 forming a bearing portion 9 for the upper end 10 of the threaded pedestal 5. The pedestal 5 is provided with a vertical groove 11 for a purpose later described.

Spaced from the upper end of the pedestal 5 is an annular groove 13 and the wall 14 of the boss member is provided with a lateral threaded opening 15 for receiving the shank of a screw 16 having its inner end engaging in the annular groove, as illustrated in FIG. 2 which retains the seat frame on the pedestal and allows the same to freely rotate thereon.

The hub 2 is cylindrical and the threaded pedestal 5 extends thereinto and while it is a fairly close fit, it will not bind therein. The hub 2 has an enlarged portion 17 and is provided with a cylindrical socket 18 of larger diameter than the cylindrical opening 19' in the pedestal forming an annular shoulder 20 in the lower portion of the socket. Adapted to engage the threaded pedestal 5 is a threaded locking nut 21 which is of less diameter than the diameter of the socket 18 and is loosely mounted in the socket by a screw 22 engaging in a threaded socket 23 in the wall of the enlarged hub portion 17. One side of the upper edge 24 of the locking nut is cut away forming a vertical side wall .25 so that the head 26 of the screw will engage a shoulder 27 formed by the cut away portion and retain the locking nut in the socket, but allow it to move with the pedestal to prevent binding of the pedestal in the hub. The vertical side wall 25 to prevent rotation of the nut with the pedestal.

Encircling the threaded pedestal 5 is a collar 28, the inside diameter of which is slightly larger than the outside diameter of the threaded pedestal 5 so that the collar will freely slide vertically on the pedestal. The collar 28 may be of any desired shape but I have here shown it to be substantially cylindrical having plain upper and lower sides 29' and 30. The inside face 31 of the collm is provided with a vertical groove 32 or notch for receiving a key '33 which extends below the collar forming a lug 344 as illustrated in FIG. 2. The key 33 has a threaded opening 35 in the outer edge thereof which registers with an opening 36 in the collar 28 for receiving an Allen screw or the like 37 to hold the key in place in the collar. The key is illustrated in FIG. 2 and engages in the vertical notch 11 of the pedestal so that the pedestal cannot rotate without rotation of the collar 28.

As illustrated in FIG. 3 the lug 34 on the key 33 depending below the collar engages in one of the notches 38 spaced in the top 39 of the floating locking nut 21 when the collar is lowered to the hub to prevent rotation with respectto the hub due to the locking of the collar, pedestaland nut together and the nut being non-rotatably mounted in the hub by the screw 22. The chair seat: frame will freely rotate on the pedestal and will always; remain the same height from the base when the pedestal is locked to the locking nut which is in turn locked to the hub.

The pedestal has a transverse bore 40 therein which tapers inwardly toward the notch 11 in the pedestal 5.

as indicated at 41 (FIG. 2). The taper at 41 forms a lip 42 to provide a stop for a ball 43 urged toward the inner edge 44 of the lip 42 by a spring 45 having one end engaging against the ball and the other end engaged against a set screw 46 engaging in threads 47 in the bore 40-opposi-te from the lip 42. The inner face 47 of the key 33 is provided with a recess 48 as best illustrated in FIG. 2 adapted to be engaged by a portion of the ball 43 extending beyond the lip 42 into the groove 11 to provide a lock in the pedestal for the collar and retain the collar in its upper position also as shown in FIG. 2.

When it is desired to change the height of the chair seat with respect to the base, the collar 28 is raised by hand and disengages the lug 34' from the notch 38 in the floating locking nut 21 and is raised vertically on the pedestal 5 until the spring urged locking ball engages in the recess 48 to retain the collar against the lower end 50 of the boss 7 as shown in FIG. 2.

' One side of the collar 28 is provided with a vertical opening 53 counter-bored as indicated at 54 for receiving a plunger 55 having a reduced shank portion 56 which extends through the opening 53 and is provided with a keeper or stock portion thereon as indicated at 56' to' retain the plunger assembled in the collar. A coil spring 57 surrounds the shank to retain the plunger 55 extended above the face 29 of the collar when in normal position. When the collar is releasedfrom the hub 2 and raised vertically the plunger 55 will engage against the lower end 50 of the boss 7 of the frame 6 and upward pressure on the collar will cause the plunger to be pressed into the counter bore 54. The lower end 50 of the boss 7 has suitable notches 58 circumferentially spaced and opening downwardly therein. The notches 58 intersect the bore 57' around the pedestal 5. Slight rotation of the seat frame 6 with the boss 7 depending therefrom will align one of the notches 58 with the plunger 55 and the spring 57 will force the plunger into engagement with a notch 58 thus locking the seat frame to the pedestal as shown in FIG. 2.

When the collar is in the position shown in FIG. 2, due to engagement of the key 34 in the vertical groove 11 in the pedestal and the plunger engaged in a notch 58 rotation of the seat frame 6 will rotate the pedestal 5 and thus raise or lower the pedestal as desired in the hub 2 due to the threaded engagement of the pedestal with the floating locking nut 21 thereby raising or lowering the seat frame. When the desired distance between the seat and chair base is accomplished by rotation of the seat frame and pedestal, the plunger is disengaged from a notch 58 in the sleeve or boss 7 by lowering the collar by hand by merely pressing downwardly thereon until the lug 34 on the key 33 will engage in the notch.

38 in the top of the floating locking nut 21 thereby looking the-pedestal against rotation. The seat frame is freely rotatable on the pedestal and since the pedestal is locked against rotation, the seat will always remain in the same spaced relation from the base through use of the chair.

It will be obvious, the locking nut 21 is mounted in the socket 18 of the enlarged portion 17 of the hub 2 so that the pedestal 5 will not bind in the cylindrical hub.

as in former devices.

locking nut 21 and holding it in place in the socket,

other forms may be utilized such as having the screw engage the side of the locking nut as illustrated in FIG. 5.

FIGURES 5 and 6 illustrate a modified form of the V V above the upstanding portion 61 having a socket 64 for receiving a locking nut 65 of less diameter than the socket 64, the same as illustrated in the preferred form of the invention. The locking nut 65 has notches 66 in the upper edge thereof and the enlarged portion 63 is provided with an opening 67 in a side wall thereof for receiving a screw 68. having its inner end engaging in a bore 69 in the side of the nut 65 for holding the same in place and preventing rotation thereof. The pedestal 5 operates in the locking nut and sleeved hub the same as in the form of the invention shown in FIG- URES l to 4 inclusive.

In FIG. 7 I have shown a still further modified form of invention wherein the base 70 has a substantially plain top 71 and 'a depending cylindrical boss or hub 72 having a cylindrical opening 73 for receiving a threaded pedestal 74 the lower end of which is provided with a lateral opening 75 for receiving a pin or the like 76 for preventing removal of the pedestal from the base without removal of the pin.

This form of the invention includes the collar 28 and has the key and plunger and locking lug as shown in FIGURES l to 4 inclusive and which are given like numbers.

Mounted upon the plain surface 71 of the base 70 V is a cylindrical washer member 77 having a flange portion 78 provided with openings registering with threaded openings 79 in the top 71 of the base for receiving screw or the like 80 for fastening the washer on the base. The

washer has an upstanding U-shaped portion 81 with the 1 inner leg thereof substantially parallel with the wall 82 of the cylindrical opening 73 in the boss 72. An internally threaded locking nut 83 is mounted upon the threaded pedestal 74 and is counter-bored as indicated at 84 forming a socket 85 which receives the U-shapedupstanding portion 81 of the washer 77, and the annular shoulder portion 86 of the nut will engage said upstanding U-shaped portion. One side of the locking nut is provided with an opening 87 for receiving the threaded shank 88 of a screw or the like 89 extending through an opening in a bracket 0 integrally formed with the washer member 77. The bracket 90 is merely a struckout portion of the flange portion 78 of the washer and 1S bent outwardly and upwardly as best illustrated in FIG. 6, sothat when the screw is in place, the locking nut 83 is prevented from rotation with the pedestal.

A dish-shaped ring member has a top portion 101 provided with an opening 102 which engages around the pedestal 74 and around the depending lug 34 of the key 33 of the locking collar 28. The open part of the dishshaped ring is downwardly toward the base 70 and is held to the lower portion of the collar 28 by the head 103 of the plunger 55 of the collar.

In operation of the structure, as shown in FIG. 6, the collar 28 or the dish-shaped ring member 190 may be grasped by the hand of the user and the lug portion 34 of the key 33 removed from the notch 105 in the top edge of the locking nut 83 and the collar moved upwardly on the pedestal 74 until it assumes the position as shown in FIG. 2 and is held upwardly by the ball and spring member 45 as shown therein. 7 Rotation of the seat and seat frame 6 will then move the pedestal with respect to the locking nut 83either upwardly or downwardly as desired. Movement of the seat clockwise will lower the height thereof and movement counter-clockwise will raise the seat with respect to the base. Removal of the locking nut 83 is accomplished by removal of the set screw 89 from the bracket 90 and the nut 83 and then the nut rotated on the pedestal 74. The pin 76 extending through the bottom end of the pedestal will prevent accidental displacement of the pedestal from the base, but by removal of the pin 76 the pedestal may be removed therefrom.

It will be obvious from the foregoing that I have provided an improved locking device for a chair base and pedestal whereby there is positive locking of the pedestal against rotation during use of the chair while the chair seat is freely rotatable on the pedestal and wherein the hub or base in the base is cylindrical and not threaded therein and is adjustably centered with respect to the cylindrical opening in the hub and the locking nut is free to move in the socket in the hub.

What I claim and desire to secure by Letters Patent is:

In a chair, the combination of a base having a hub with a vertical cylindrical opening therein, a threaded pedestal engaging in said vertical opening in the hub, a seat having a frame normally rotatably mounted on the upper end of said pedestal, a washer member having a central cylindrical opening and a boss surrounding said opening carried by said base, a threaded locking nut having a downwardly opening socket member in its lower face for receiving said boss on said washer, said nut being nonrotatable and engaging said pedesetal and movable laterally With respect to said cylindrical opening in said hub, means on said washer having engagement with said nut to prevent rotation of the nut with respect to said base, means on said pedestal cooperating with said seat frame to prevent rotation of said seat with respect to the pedestal so that rotation of the seat will move the pedestal vertically with respect to said base, and means on said last named means cooperating with the locking nut to prevent rotation of the pedestal when the seat frame is in rotatable position with respect to said pedestal.

References Cited in the file of this patent UNITED STATES PATENTS 825,822 Gilson July 10, 1906 1,107,780 Germanson Aug. 18, 1914 2,368,748 Doty Feb. 6, 1945 2,987,110 Cramer June 6, 1961 

